Java 当值在变量中时，使用 replaceAll 替换大括号字符串，java 8

Question

我有一个变量：

String content = "<xxx.xx.name>xxx.xxx.com:111</xxx.xx.name>";
String destination = "\$\{VAR\}";
String source = "xxx.xxx.com:111";
content = content.replaceAll(source, destination);

结果：

result = {IllegalArgumentException@781} Method threw 'java.lang.IllegalArgumentException' exception.
detailMessage = "Illegal group reference"
cause = {IllegalArgumentException@781} "java.lang.IllegalArgumentException: Illegal group reference"
stackTrace = {StackTraceElement[5]@783} 
suppressedExceptions = {Collections$UnmodifiableRandomAccessList@773}  size = 0

但如果我这样做：

content = content.replaceAll(source,"\$\{VAR\}");

一切正常。我如何模仿或修复 replaceAll？

Answer 1

来自 String.replaceAll(String, String) 的文档：

Note that backslashes (\) and dollar signs ($) in the replacement string may cause the results to be different than if it were being treated as a literal replacement string;

强调可能，这可能会失败，具体取决于您的 Java 版本（尽管我无法通过 Java 8、11、 12、15 and even the early access Java 16)

您可以使用 Matcher.quoteReplacement(String) 转义替换字符串中的 \ 和 $ 字符，如稍后在 javadoc 中所述：

Use Matcher.quoteReplacement(java.lang.String) to suppress the special meaning of these characters, if desired.

因此将您的代码更改为（假设您要将内容替换为 ${VAR} 而不是 ${VAR\}）：

String content = "<xxx.xx.name>xxx.xxx.com:111</xxx.xx.name>";
String destination = Matcher.quoteReplacement("${VAR}");
String source = "xxx.xxx.com:111";
content = content.replaceAll(source, destination);

这导致：

<xxx.xx.name>${VAR}</xxx.xx.name>

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